[Auditory neuropathy: audiologic and clinical evidence]

ABSTRACT

The disorder known as "Auditory neuropathy [AN]" is not new but has recently become more clearly defined and understood. Auditory neuropathy is a form of hearing impairment in which the cochlear function is normal but neural transmission in the auditory pathway is disordered. This condition accounts for approximately 7% of permanent childhood hearing loss and 0.2-4% of high risk neonates. Case Reports Four children [three boys and one girl] younger than two years with auditory neuropathy symptoms are presented. Based on audiologic and clinical findings there were high risk factors in two cases. In each case, absent auditory brainstem response [ABR], absent acoustic reflexes, present cochlear microphonics [CM] and present transient evoked otoacoustic emissions [TEOAE] were shown. This section discusses the clinical profile of cases regarding etiology [neonatal insults, infectious processes, genetic and syndromic factors], age of symptom onset, prevalence of AN/AD, outer hair cells function, audiogram, and acoustic reflexes in relation to other studies